1. Field of the Invention
The present invention relates to a metallic hollow golf club head and, more particularly, to a large golf club head such as a driver.
2. Description of Related Art
As a wood-type golf club head such as a driver and a fairway wood, metallic hollow golf club heads have been widely used. Generally, hollow wood-type golf club heads have a face part for hitting a ball, a crown part constituting the top surface portion of the golf club head, a sole part constituting the bottom surface portion of the golf club head, a side part constituting the side surface portions on the toe side, back side, and heel side of the golf club head, and a hosel part. In this hosel part, a shaft is inserted and fixed by an adhesive or the like.
As a metal forming the hollow golf club head, an aluminum alloy, stainless steel, or titanium alloy has been used, and especially the titanium alloy has been used widely in recent years.
To increase the shot carry of a metallic hollow golf club head, development for increasing the rebound of the ball by utilizing the deflection (trampolining effect) of the face surface has been carried out.
Also, Japanese Unexamined Patent Application Publication No. 2005-211438 discloses a golf club head in which the carry is increased by making the crown part easily deflectable.
Since the golf rules governing the upper limit of the rebound coefficient have been revised, carry now has to be increased by other measures. In the case of what is called a high-rebound type golf club head utilizing the trampolining effect, although a long carry can be attained when a ball is hit by the face center, such a long carry cannot be obtained when the hit point deviates from the face center.
For the golf club head described in Japanese Unexamined Patent Application Publication No. 2005-211438 as well, if the hit point deviates from the face center, the carry does not increase so sufficiently.